Improved Heat Dissipation and Optical （提高散热和光学）.pdf

Presented at the 6th International Conference and Exhibition on Device Packaging, March 9 – 11, 2010, Arizona, USA Improved Heat Dissipation and Optical Performance of High-power LED Packaging with Sintered Nanosilver Die-attach Material 1 2,3 3 4 2 Paul Panaccione , Tao Wang , Xu Chen , Susan Luo , and Guo-Quan Lu 1 Luminus Devices Inc., 1100 Technology Park Dr., Billerica, MA 01821 2 Dept. of MSE, Virginia Tech, 213 Holden Hall, Blacksburg, VA 24061 3 School of Chemical Engineering, Tianjin Univ., Tianjin, China 4 NBE Technologies, LLC, 2200 Kraft Dr., Suite 1425, Blacksburg, VA 24060 ppanaccione@ Abstract Heat removal in packaged high-power light-emitting diode (LED) chips is critical to device performance and reliability. Thermal performance of LEDs is important in that lowered junction temperatures extend the LED’s lifetime at a given photometric flux (brightness). Optionally, lower thermal resistance can enable increased brightness operation without exceeding the maximum allowable Tj for a given lifetime. A significant portion of the junction-to-case thermal resistance comes from the joint between chip and substrate, or the die-attach layer. In this study, we evaluated three different types of leading die-attach materials; silver epoxy, lead-free solder, and an emerging nanosilver paste. Each of the three was processed via their respective physical and chemical mechanisms: epoxy curing by cross-linki